Casing for electrical apparatus



W. O. DWYER.

CASING FOR ELECTRICAL APPARATUS.

APPLICATION FILED OCT. 22. 1920.

1,425,843, Patented Aug. 15, 1922.

2 SHEETS-SHEET I.

Fig.1.

W. 0. DWYER.

CASING FOR ELECTRICAL APPARATUS.

APPLICATION FILED 0C1- 22 I920.

Patented Aug. 15, 1922.. A

2 SHEETS-SHEET 2.

Fig.2.

Inventor"; William ODwyer,

HIS Attorney.

UNITED STATES PATENT OFFICE.

WILLIAM 0. nwYEa, or: PITTSFIELD, massaoimsnrrs, assienoa 'ro GENEBALE EC, TRIO comramr, a oonroaarlonor NEW ORK. a

' cas'nve ron ierino'rmcan arrsnafirns. i

1,425,843. n e ee ev st l" Patented flii'ik ii 15, 1922. o i i Applicationflled October22, 192th Serial'No. 418,842.

To all whom it may camera: 1 i

Be'it known that I, WILLIAM O DWYER, a subject of the King of Great Britain, re-

siding at Pittsfield, in the county of Berk-- shire,'State of Massachusetts, have invented certain new -and usetul Improvements-in Casin s for Electrical Apparatus, of which the fo lowin is a specification. M My invention relates to casings for ele'stiical' apparatus-submerged in-oil, such as transformers and the liken-mm 1 In electrical apparatus ofithi's type,-it has become the practice, -particularlyfor large units and for high voltages, to, fill the mm casing: completelynwith oihisinoe the exclusion of the air therefrom hasi many zadvantages in addition m ths-reduction in the size of the tank on casing required. ,gPreerni nent amongsuchfiirdvantagesis' :the avoidance of sludging or v-rapidjaoxidizing-of the oil andthe general exclusion, of moisture from theioil in the main casing which tends to decrease the dielectric strength of theoil. This practice has led to the use of auxiliary tanks. or casings, sometimes called conserva'tors in? comunctionw with the maintank or casing in order to-accommodate theexpansion-andcontraction of the oil due to changes in the load or other-causes. 1

The eneral object of my invention is accordingly to provide animproved arrangement of parts, where such oonservators are used, WhlCh will'be economical, efficient and readil manufactured, and in-which ;t-here is litt e likelihood of the .moisture collected therein bei drawn therefrom-over into the main ta or casin In accomplishing this'object the auxiliary tank is secured and connected ;tothe:main tank in a manner providing free intercommunication betweenthe oil contents of the two tanks and for the collection "and re-' moval of the moisture at a pointindependent of and preferably remote from the communicating connection. a v

, Further objects and advantages of my invention will appear, and a more-complete understanding thereof may be had from the following detailed description taken in conjunction with the accompanying drawings in which: i 1- Fig. 1 is a view, mainly inside elevation, of a casing for a transformer equipped with m invention; Fim'Q is a fragmentary view ot a portion of the device shown in Fig. 1'

.Q z' x1 5". i'itaken me plane at right anglesto-the plane" ofFig. 1; and Fig. 3vshows a modified em bodimentofmy invention:

min" t 1. Referring :now to Fig. .1 of theddrawingsy l0 denotes atank-orzcasin ,"hereeshownzas' provided w'ithexternal ra iatorszlly-which tank is adapted .to house :the::trans6rmer or other electrical lappalratiiswhoset main; cooling mediumis theyoil or!other.='insulating fluid in the tank. -rQT-c soul-1w; n?!

The radiators 11 are. shownaslattached to-the tanklor casi n10 byimeanshof1t'0p and bottom pipe coup ingsiorelbows 12=ahd 13; ermittingaread vcirculatiinr oh the; oil t erethrough-and 'a so-providin'gaireadyi means for detachment: ,1 Tanks-thusequipped are generally mounted on ,portable vb'ases, suchas shown at 14. I? m is I The auxiliary tank or:-f-conservator-..=for accommodatin .th'e: expansion and -=oontraction of the oi? filling theomainatank 10,1is shown at '15, andis supported; adjacent the main tank by a suitable framework--16 at-- tached thereto. Thisauxiliary itank'communicates with the main tank throughtthe pipe connection 20 which preferably contains a valve, as shown at21, for a pn ose hereinafter more fully pointed, out. Clhe pipe 20 leads preferablyhfrom a ipoint near the bottom of auxiliary tank'151and enters tank 10 substantially at the highest oint to which-the oil content thereof exten -.The pointofentrancehere shown isin the side of an upwardly projecting boss=22 formed on the cover 23 ofitank-10 as shown most clearly in Fig. 2. This-boas serves as a convenient means for securing the escape -pipe 24 thereto, over the upper end of which pipe is secured a thin diaphragm 25. "This diaphragm may be of any suitable material, .for' instance a metallic diaphragm which has been treated to resist corrosion and is pro: portioned so as to rupture under excessive gas pressure and hence serves as anemergencyexit for ases which-may begenerated within the tan 10 by the occurrence of-ra transient disturbance such as a short circuit.

The auxiliary tank, in accordance with my invention, is equipped with a .so-called breather as shown at30, in Fig. 1, which comprises a chamber 31 open at its lower end to the atmosphere and containing a suitable dehydrating. agent such as calcium chloride for absorbing moisturelfrom ,the air passing therethrough. The upper end of the chamber 31 communicates with the auxiliary tank by means olf a. pipe 3}; which enters the th'nk tliroii hth e bottom of :i depending portion or'di'um 33 formed on the auxiliary tank. The pi e 32 projects upwardly and reaches substantially to th el top; 0.5 the auxiliary tank as shown. The depen in'g drum '33 is designed to serve as a sump in which to collect the water or moisture which has gotten into the oil. Accordingly; it'is desirable so'to locate this drum that there will be little likelihood of the water or moisture collecting here getting intoithe main tank. To this end the drum 33 is loeatedrindbpendently of: and helow'the entra-nce'of: pipe ihto the auxiliary tank 152"filiis location in the bottom of the auxiliiiry tank is also preferably somewhat remoto'from'the entrance of pipe hence the position adjacent one end of the till):- iliairy! tank asrshown;

r111 hrdemthat the-water-or moisture which '--in 'the; drnm"=33' "may be' readily drained ofl, referabl v at regular intervals, itjispr'ovid e with a drawmfi cook 34. In addition-to'the-"breather this tank is provided witha safetyvalv'e 35 wh-ieh' is clearly shown in Fig. 2, and is a/da-ptml'topermitoi' a--' 'm( 'i-e =-rapid:"egress of gases thanthe breather? will accommodate;

The operation ofthis form of my invention is-as follows: When the main tank 10 and the iiuxiliary tank 15 are properly filled withxoi l a'nd communication is established thioughjpi e 20, normal expansion and contraction o 'the'oil, due to changesin the load-"Orin the ambienttemperature. are accohflinodated by'the passageof air or breathing-thhou'ghthe breather" together with a .rise and'fallo'f theoil head in thoauxiliarv iniikfsuoh head being pieferably visually ascei'tainedf'by means of'iil gauge glass'as sli'owna't 36." Abnd'rmally r9; )id expansion or the genera-tionof'gas wit in the main tank oIi-"the otlier hand is permitted to spend: itself'harmlessly through the exits l"- forded-"bj the safety valve 35 and the escape i -24; "%hen it is desired to remove from the tank, a' bnshing, such as shown at 37, or to change the tap 'eoh'nectionsi it is not necessary filstto remove the oil from the anxiliary' tank 15 as would be the case were the com'mnnicatingpipe 20- n'ot' pro vided with u valifefllhS shown.- In'the case illustrated. however, all that is necessary is to close (his valve, t-herehy'confi'ning; the excess oil to tile au'igilieiy' tank while the bushing i's h'ing remove t-ank 'is otherwise open.

"In the modified form shown in Fig. 3, the main tankao is illustrated-as equipped with auxiliary tank 41 and communicates there with throughpipe connection 42which is not provided with a'shutfofiwalve oi" any or while uniope'ning into the main Mme? kind. The auxiliary tank 41 has ing sump ill through the bottom of which entersihe fbreather pipe 44 fromthe dehydrating charnl'iei' 45' of the hreather" proper. The sump 43 is shown as provided with 'a draw oli cook 46.

The operation of this form of nix invention will readily be understood irom the description of: the operation given above.

Having now described what is at present the best means known to me tor carrying out an embodiment of my invention, I would have it understood that such means are merely illustrative andthat I do not mean to be limited therelziyto the exact details shown nor restricted in the choice of recognized equivalents ex'ce t'as defined in my claims hereunto appen ed.

hat I claim as new and desire to secure by Letters Patent ofithe United. States,

1. The combination with a mairr casiug for electrical.appa.ratus, of. an auxiliary casing secured to the main casing and pro.- vided with? a passage establishing-comlmmication with the main casing, and an insulate ing liquid withinsaid main casing. and extending through saidpassage into the auxiliary casing,'said auxiliary casing. being provided 'witli a dependinportion independent ofi said. passage an -locatedbelow t-heentranoe ofsaid passage thereinto'.

2. The combination with'a main casii'ng for electrical apparatus, of an auxiliary casinsecured to the main 'casi ng and provide with a passage establishing communication withthe main casing, an insulating li uid within said main" casing and: exten ing through said passage into the auxiliaryeasing, said auxiliaryeasingheing provided with :1. depending portion independenthof said passage and below its entrance into-the auxiliary casing, aiid a pipe opening toithe atmosphere extending up through said depending portion into the auxiliary casing.

' 3. The combination with a maiucasing for electrical apparatus," of an auxiliary casing secured to the main casingand'provided' with a assage establishing communication withthe haincasing,andaninsulatingli uid within 'saidmain casing and exten ing through said passage into theauxiliary cas ing, said auxiliary casing being provided with a depending portion having a drain, sa id depending portion being independent of said passage and locatedbelow itsentrance 120 into the auxiliary casing, and a bi'e'ather pipe entering said depending portion and extendingup into'the auxiliary'casingf' 4. The combination with a main casing'for electrical apparatus adapte'd to contm'na 125 fluid insulating medium, of an auxiliary cas ing secured to'the main' casing andprovided with ii. passa e"establishing"communication with the main casing, said auxiliary ensin being 'fo'rmed'with' :1 depending portion in- 130 a dependdependent of said passage and provided with a drain, and a shut-off valve located in said passage.

5. The combination with a main casing for electrical apparatus adapted to contain a fluid insulating medium, of an auxiliary casing secured to the main casing and provided with a passage establishing communication with the main casing, said auxiliary casing being formed with a depending portion independent of said pamage, located below its entrance into the auxiliary casing, and provided with a drain, a pipe communicating with the atmosphere entering said depending portion and extending up to a point adjaeent the top of the auxiliary casing, and a shut-off valve in said passage.

6. The combination with a main casing for electrical apparatus adapted to contain a fluid insulating medium, of an auxiliary casing secured to the main casing and provided with a passage establishing communication with the main casing, said auxiliary casing being formed with a depending por tion independent of said passage lM-ated below its entrance into the auxiliary casing and provided with a drain a breather pipe entering said depending portion and extending u to a point adjacent the top of said auxiliary casing and a shut-off valve in said passage,

7. The combination with a main casing for electrical apparatus adapted to contain u fluid insulating medium, of an auxiliary ing secured to the main casing and provided with a passage establishing communication with the main casing, said auxiliary casing being formed with a depending portion independent of said passage located below its entrance into the auxiliary casing and having a drain, a breather pipe entering said auxiliary casing through said depending portion, and means accommodating excessive expansion from said main casing.

In witness whereof, I have hereunto set my hand this nineteenth day of October, 1920.

WILLIAM O. DW'YER. 

